Question

What is the mass in grams of 7.5 x 10^15 atoms of nickel, Ni?

Answer 1

Answer:

7.3 × 10⁻⁷ g Ni

General Formulas and Concepts:

Math

Pre-Algebra

Order of Operations: BPEMDAS

1. Brackets
2. Parenthesis
3. Exponents
4. Multiplication
5. Division
6. Addition
7. Subtraction

• Left to Right

Chemistry

Atomic Structure

• Reading a Periodic Table
• Using Dimensional Analysis
• Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

Explanation:

Step 1: Define

7.5 × 10¹⁵ atoms Ni

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of Ni - 58.69 g/mol

Step 3: Convert

1. Set up:                              $\displaystyle 7.5 \cdot 10^{15} \ atoms \ Ni(\frac{1 \ mol \ Ni}{6.022 \cdot 10^{23} \ atoms \ Ni})(\frac{58.69 \ g \ Ni}{1 \ mol \ Ni})$
2. Multiply:                                                                                                           $\displaystyle 7.30945 \cdot 10^{-7} \ g \ Ni$

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

7.30945 × 10⁻⁷ g Ni ≈ 7.3 × 10⁻⁷ g Ni